Process and apparatus for producing continuous strip elements of printing forms



6 1 2 t 6 e 1 e 4 .n n w e l R.e T h s S S 3 U m N MS M R CO5 2 YMG l W... m3 h R m a F 0M m 1 M Ma: E L E 192 Jan 7 P. s. MURPH PROCESS AND APPARATUS FOR PRODUCI Patented Jan. 18, 1927.

UNITED STATES PATENT OFFICE.

PETER s. MURPHY, OF WASHINGTON, DISTRICT or COLUMBIA.

PROCESS AND APPARATUS Pox PRoDUcING coN TIN UoUs STRIP ELEMENTS OF Pnm'rmq Forms.

Application filed March 3, 1925. Serial No. 12,982.

This invention relates to the production of printing forms, such as spacing material, leads, slugs, rules and the like, by a cast ng process of the character disclosed and claimed in Patent #1,230,758, granted to Amos L. Knight, on the 19th day of February, 1918.

In the practical application of the process above referred to, successively congealed sections of type metal are fused together to form an integral structure or strip of predetermined width and depth and of any desired length. This is accomplished by pumping molten type metal into asuitable mold unit having one wall in the form of a matrix to determine the facial characteristics of the finishedstr'ip or product, the metal being caused to congeal within the mold and being then fed forwardly by the mold blade to provide for the introduction of a succeeding charge of molten metal and to close the open end of the mold during the casting of saidsucceeding charge. The congealed product is prevented from being blown out of the mold 0n the working stroke of the pump piston by clamping the product between the type bars or sides of the mold. The length of product produced in each casting operation is determined by the clearance between the forward edge of the retracted mold blade and the opposing wall of the mold which is the inner end of'the previously cast section of the product. This clearance is varied, within the capacity limits of the mold, by regulating the effective stroke of the mold blade.

In one form of mold used for carrying out the above process, the requisite clamping pressure exerted on the product is applied through the agency of an intermittently operated screw forced against one side of the mold during each casting operation and then retracted to permit free ejection of the product. In another later form of mold the intermittent operation is dispensed with and the screw permitted to apply pressure to the product during the ejection as well as during the casting operation.

In using both forms of mold, I have observed that the pressure screw is so affected by the changing temperature of the mold that when the latter becomes comparatively cool, as occurs under certain conditions of operation, the contraction of the screw materially reduces, the clamping pressure exerted on the product with the result that the product is frequently blown from the mold with disastrous effects appreciated by skilled artisans. lVith reference to the form of mold in which the pressure screw is permitted to apply pressure on the product during the ejecting operation, I have also observed that the expansion of the screw, which occurs when the mold is highly heated, increased the pressure on the product to an extent which frequently caused the mold blade to hang up in the mold. This hanging up of the mold blade is usually attended by an ob'jectionably loud banging noise and by the creation of other unfavorable conditions which, even when partially remedied by adjustment of the screw, eventually make it necessary to dismantle and clean the various parts of the mold unit.

These observations have led to the development of the present invention with the primary object of providing, as a substitute for the aforementioned screw, pressure-applying means effective at all times to prevent the product being blown from the mold during the casting operation while permitting it to be advanced freely by the mold blade during the ejecting operation.

A further purpose is to provide pressureapplying means immune from contraction or expansion in response to changing temperature of the mold, said means being in the form of a clamp entirely separate from the mold and capable of being readily applied to the standard monotype material making machine.

A still further purpose of the invention is to provide pressure-applying means which permits the product to slip, within safe limits, during the casting operation whereby more metal is caused to enter the mold and a longer cast produced for a given stroke of themold blade without impairing the fusion of successive castings.

A still further purpose of the invention is to provide pressure-applying means which face and provides a substitute for the roller 110w used on the standard monotype material making machine for accomplishing the same purpose.

Other purposes and advantages of the invention will suggest themselves to persons skilled in the art in the light of the following detailed description and accompanying drawings, in which:

Figure 1 is a top plan view of a section of the well-known monotype material making machine with the invention applied thereto,

Figure 2 is a section on line 2-2 of Fig. 1, showing the members of the clamp gripping the product therebetwcen,

Figure 8 is a similar section showing the clamp members separated to release the product,

Figure 4 is a section on line dl of Flg. 2,

Figure 5 is an enlarged, detailed view in perspective of the movable member of the clamp,

Figure 6 is a detailed view of the rocker,

Figure 7 is a perspective view of a guide for the product,

Figure 8 is a top plan view of a modification of the invention, the latter being shown applied to the machine,

Figure 9 is a side elevation of the structure shown in Fig. 8,

Figure 10 is a section on line 1010 of Fig. 9,

Figure 11 is a fragmentary perspective view of the movable clamp member showing the sliding j aw face carried thereon, and

Figure 12 is a fragmentary perspective View of the stationary clamp member.

The general construction and operation of the monotyp-e material making machine for which the present invention is designed is well-known to those familiar with the art and need not be described in detail. Reference will be had therefore only to such parts or units of the machine as are essential to a proper understanding of the invention. The mechanism through which the power is transmitted to the various parts of the machine includes an oscillating lever A having the usual stud B engaged in the arm C of the rock-shaft D. This shaft is provided with a' longitudinally extending slot or groove E which is utilized for the purposeof the invention as hereinafter explained. On the bed F is arranged the mold G in which successive charges of molten type metal are cast and fused together to form the continuous strip product H. This mold, as previously explained, is equipped with a pressure screw (not shown) serving to clamp the product during the casting operation and for which the present invention is substituted.

The form of invention disclosed in Figs. 1 to 7, inclusive, provides a stationary clamp member 1 arranged at one side of a cut-out formed in a guide 2 such as is usually provided for guiding and steadying the product H as it comes from the mold. At the opposite side of the guide is arranged the movable member of the clamp including a jaw 3 having its gripping surface covered by suitable padding 4 secured thereto by screws 5 or other fastening means. This jaw is carried at one end of a rod 6 slidable through a cylinder 7 consisting of two separable parts between which is clamped a block 8 carrying trunnions 9 by which the cylinder is mounted for vertical swinging movement between a pair of supports 10. These supports are removably anchored to the bed F of the machine by bolts 11. A spring 12, encircling the rod between one end of the cylinder and a suitable abutment 13 on the rod, normally tends to force the jaw 3 in the direction of the stationary clamp member 1. Rearwardly of cylinder 7 the rod extends through an opening in a block 13 pivotally supported within a cut-out in a rocker 1 1. A spacing sleeve 15 encircles the rod beyond the outer face of block 8 and is held in position bylock nuts 10. The rocker is shown in detail in Fig. 6 and is preferably made of a single piece having its lower edge tapered, as at 17, to fit within the groove E of the rock-shaft D by which it is actuated.

When the rocker is moved rearwardly by the shaft, the abutment of block 13 against sleeve 15 draws the rod back, separating clamp members 1 and 3 and compressing spring 12. On the forward movement of the rocker, the spring forces the rod forwardly to clamp the product between the clamp members. The timing of shaft D with reference to the operation of the mold is such that the clamp members will be caused to grip the product during each casting operation and to subsequently release the product to permit the same to be advanced freely by the mold blade during the ejecting operation. Due to the fact that the rocker moves in the arc of acircle, it will be evident that the rod has a vertical rocking movement in addition to its sliding movement, the purpose being to enable the jaw to engage and press down on the product so as to force it as low as the bed or guide of the machine will permit. By holding the product down in this fashion during the casting operation, warping isprevented and each cast is caused to come out of the mold true and without any defects such as sometimes occur as a result of the tendency of the product to warp upwardly as it comes from the mold. To guard against any turning movement of the rod and jaw I provide a strip 18 having one end secured to the block and the other end engaging the upper edge of the jaw. It will be understood, however, that this strip may be replaced by any equivalent means capable of accomplishing the same function.

. From the preceding description it is evident that my invention provides a separate clamp which operates at a .point sufficiently remote from the mold to eliminate any possibility of the pressure exerted by the clamp being adversely affected by the changing temperature of the mold, as occurs with the use of the pressure screw for which this invention is substituted. The clamp of the invention is of further advantage in that under certain conditions it will permit the product to slip within safe limits during the casting operation whereby more metal is caused to enter the mold and a longer cast obtained. These safe limits can be readily determined by an experienced operator as the main requisite is that the product shall be prevented from slipping beyond the matrix during the casting operation since this would open the mold and result in squirting of the metal. The manner in which a longer cast is produced by the aforementioned slipping movement of the product during the casting process will be understandable from the following reference to the construction of the mold in which the casting takes place. In this type of mold, the clearance between the retracted mold blade and the opposite wall of the mold '(whichis formed by the inner end of the congealed product) can be varied only by adjusting the effective stroke of the mold blade and the necessary adjustment must be made, of course, prior to the operation of the mold. This adjustment is obtained mainly by varying the back stroke of the mold blade because only a very limited adjustment is permissible with reference to the forward stroke of the blade, for the reason that if the forward stroke of the blade is permitted 'to push the product too far beyond the opening inthe mold base through which the metal is injected no fusion will occur or, if it does occur, will be of a very poor-quality. In other words, if the forward stroke of the blade is lengthened to push the product as far as it willrgo without passing beyond the matrix and thus opening the mold, then the inner end 'of the product will be beyond whatmay be termed the fusion region and hence the requisite fusion will not occur. I have found, however, that under certain conditions if the product is {permitted to slip during the casting operation, and in response to the pressure developed within the mold, the fusion obtained will be of good quality and the lengthening of the mold cavity by the slipping movement of the product willenable more metal to enter the mold for producing a longer cast. It is, of course, necessary that this slipping movement be controlled and terminated within safe limits to prevent the product being blown from the mold. Generally speaking, these safe limits may be said to extend from the opening in the mold base to the end of the matrix.

In the modification disclosed in Figs. 8 to 12, inclusive, the stationary member of the clamp is of T-shape and has the stem 19 slotted and anchored to the bed of the machine by bolts 20 which may be loosened to permit 5 adjustment of the member as occasion requires. The head 21 is lined up with the mouth of the mold and serves as a guide for the product ejected from the mold, the end of the-head adjacent the mold being beveled,

latter being disposed in front of the plate 23 and having a guide slot 25 through which project the supporting studs 26 which may be in the form of removable screws. The two plates are normally held in the full line position shown in Fig. 10 by means of a spring 28 having one terminal connected to an L-shaped extension 29 on the slidable plate and the other terminal connected to the rear side of the stationary plate :as indicated at 30. At the end opposite that connected to the spring, the movable plate 24 is equipped with an adjustable stop-screw 31 engageable with the corresponding end of the stationary plate 23 to limit the extent to which the slidable plate may be .moved against the resistance of the spring 28; the limit of movement in the opposite direction being determined by the abutment of one of the studs 26 with the adjacent end of the slot 25. If desired, any suitable form of friction-reducing means may be interposed between the two plates to facilitate their relative movement. When this form of clamp is first engaged with the product and a cast is being made, the plate 24 occupies the position indicated in full lines in Fig. 10, with the screw 31 spaced from the adjacent edge of plate23. Hence, plate 24 is free to slide within a safe distance as shown by the dotted lines, and this sliding movement of the plate allows the product H to slip during the casting operation so that a longer cast is produced as set forth with reference to the structure disclosed in Figs. 1 to 6. \Vhen the plate 24 reaches the limit of its slide and comes 'to a dead stop, the product H is no longer permitted to slip but is held fast by the clamp until the casting is completed, at which time the clamp is released to let the product be ejected from the mold. lVhen the clamp is released from the product, the retraction of spring 28 draws the plate 24 back to its original position.

From the above it will be seen that the invention provides for the periodical clamplli) lit)

ing and releasing of the cast product in an el'licient and practical manner and it has been found, in practice, that the output of a machine is greatly increased by the application of the invention thereto, since it enables the machine to be operated at the highest speed for which equipped. Being outside of the mold and easy of access the clamp is at all. times visible to the operator and can be easily adjusted and taken apart whenever required. It will be understood, also, that the invention is susceptible of further changes and modificationswvithin the scope of the appended claims.

Having thus described the invention, what is claimed is 1. In a monotype material making machine, the combination with the mold of a separate clamp functioning to, grip the product exteriorly of the mold during the casting operation and to release said product upon completion of the cast.

2. In a monotype material making machine, the combination of an oscillating shaft, a mold in which the product is cast, stationary and movable clamp members between which the product passes as it issues from the mold, a spring normally urging the movable member toward the stationary member to clamp the product during the *asting operation, and a connection between the oscillating shaft and the movable member functioning to retract the latter against the resistance of the spring to release the product upon completion of the casting operation.

3.In a monotype material making machine, the combination of a clamp located exteriorly ot the mold but adjacent to the opening through which the product is ejected, said clamp comprising a pair of co-acting members between which the product passes as it issues from the mold, and means for causing said members to grip the product during each casting operation and to release same upon completion of each cast.

4. In a monotype material making machine, the combination with the mold, of means for gripping and exerting a downward pressure on the product during the casting operation.

5. A product clamp formonotype material making machines comprising a pair of co-acting members between which the product is clamped during the casting operation, means for moving onemember to and from the other member, and means for causing the movable member to exert a downward pressure on the product as it engages therewith.

6. A product clamp for monotype mat rial making machines, comprising stationary and movable members between which the product is gripped during the casting operation, means supporting the movable member to slide to and from the stationary memher and to pivot about a horizontal axis, and means acting periodically to cause the movable member to slide to and from the stationary member, said last named means including provision for swinging the movable member about its horizontal axis in such manner as to cause said movable member to exert a downward pressure on the product as it engages therewith.

7. In a monotype material making machine, the combination with the mold of a clamp comprising stationary and movable nembers positioned at opposite sides of the ejection point of the mold 'to permit the ejected product to pass therebetween, the stationary member serving as a guide for the product, and means operatively connecting the movable member to the operating mechanism of the machine to cause said movable member to periodically approach and recede from the stationary member.

8. In amonotype material making machine, the combination with the mold of a stationary member arranged on the bed of the machine in line with one side of the mold discharge opening to provide a guide for the product as it issues from the mold and having the end nearest the mold presenting an inclined deflecting surface, and a movable memberco-acting with the stationary member to grip the product during the casting operation.

9. A product clamp for monotype material making machines comprising a pair of coacting members between which the product is gripped during the casting operation, and a sliding jaw-face carried by one of said members.

10. A product clamp for monotype material making machines comprising a pair or" co-acting members between which the product is gripped during the casting operation, a sliding jaw-face carried by one of said members, and adjustable means for limiting the sliding movement of the j aw-face in one direction.

11. A product clamp for monotype material making machines comprising a pair of co-acting members between which the product is gripped during the casting operation, a sliding jaw-face carried by one of said members, and a spring resisting sliding movement of the j awn ace in one direction.

12. A product clamp for monotype mate rial making machines comprising a pair of co-acting members between which the product is gripped during the casting operation, a sliding jaw-face carried by one of sait members, a spring resisting movement of the sliding jaw-face in one direction, and adjustable means for limiting the extent to which the jaw-face may travel against the tension of the spring. 7

A3. A product clamp for monotype ma terial-making machines comprising a pair of coacting members between which the product is gripped during the casting operation, one of said members consisting of a stationary plate having supporting studs and a slidable plate disposed in front of the stationary plate and having a guide slot through which the said studs project, said slidable plate having an L-shaped extension at one end, and a spring having one terminal connected to the said stationary plate and the other terminal connected to the said L-shapcd extension of the slidable plate.

14-. A product clamp for a type-casting machine comprising a pair of coacting members between which the product is gripped during the casting operation, one of said members consisting of a stationary plate having supporting lugs projecting from the front face thereof and a'slidable plate disposed in front of the stationary plate and having a guide slot through which the said studs project, said slidable plate having an L-shaped projection at each end, an elastic connection between the said stationary plate and one of the said L-shaped projections, and a stop-screw threadedly engaged in the other L-shaped projection for abutment with the adjacent end of the said stationary plate.

15. A product clamp for a material-casting machine comprising a stationary guide, a movable clamp member opposed to the said guide and consisting of a rod having a clamping aw at one end, a cylinder in which the said rod is slidably supported for longitudinal movement with respect thereto, said cylinder being pivotally supported for vertically swinging movement, a spring within the cylinder and engaged with the said rod to normally position the latter with the said jaw projected against the said guide, a spacing sleeve encircling the rod adjacent the outer end of the latter, lock nuts beyond the said sleeve, a block slidable on the said rod between the said sleeve and the said cylinder, a rocker pivotally connected with the said block, and a rock-shaft having a groove in which the lower edge of the said rocker is seated.

16. A product clamp for a material-casting machine comprising astationary guide, a movable clamp member opposed to the said guide and including a rod having a jaw at one end, and abutment-providing means at theother end, a Support in which the said rod is free to slide, said support being pivotally mounted for vertical swinging movement, a block slidable on the said rod between the said support and the said abutment-providing means, a rocker pivotally connected with the said block, and a rock shat't having a groove to receive the lower edge or the said rocker.

17. A product clamp for a material-casting machine comprising a stationary guide, a movable clamp member opposed to the said guide and including a rod having a jaw at the end nearest the guide, a cylinder in which the said rod is slidably supported for longitudinal movement therethrough, a block in which the said cylinder is rigidly supported, said block being pivotally mounted for vertical swinging movement, actuating means moving in the arc of a circle to impart both a vertical rocking movement and a longitudinal sliding movement to the said rod, and a fiat strip having one end secured to the said block and the other end engaging the upper edge of the said jaw.

18. A product clamp for a material-casting machine comprising a stationary guide, a movable clamp member consisting of a rod disposed at a right angle to said guide and having a jaw at the end nearest the guide, said rod being pivotally mounted to swing about a horizontal axis and being free to slide longitudinally, and actuating means moving in the arc of a circle to impart both a vertical rocking motion and a longitudinal sliding movement to the said rod.

In testimony whereof I afiix my signature.

PETER S. MURPHY. 

